Something I’ve known myself for quite a while but felt it should be echoed here. The Parallels Virtuozzo product in my own personal opinion is although a great concept it is a terrible implementation. The Windows implementation itself is beyond problematic with numerous issues in installing useful things onto containers, roles that can’t be added, templates that never work correctly, the inability to stop and start things sometimes. 90% of the time the only way to fix an issue is to reboot the entire node which if you’re hosting a few important containers under an SLA is a headache in itself.

Linux containers are usually the better ones with the least amount of issues, however, recently I personally came across a good example of why it’s pretty poor. A particular users container decided that it wouldn’t restart so a simple ‘stop / start’ from virtuozzo itself should have really been all that was needed to sort the container but things aren’t that simple unfortunately with virtuozzo. After almost an hour of trying to stop the container and kill any processes that were running inside it the only solution was to restart the node taking all other happy users offline. A number of posts are out there especially on the Parallels KB which didn’t on this occasion did not work and in most cases when it comes to stuck containers never really do.

A larger headache can exist on the Windows containers when you discover it’s unable to do anything due to a lock file, you can’t move the container, edit the container, stop or start the container. In then turns out that the so-called ‘lock file’ does not exist in windows so again you cannot resolve the issue without rebooting the node with even tricks suck as ‘–skip-lock-file’ become useless.

Ok, so my rants out the way now…. ish. Parallels Virtuozzo is a great concept of cost effective VPS containers that allow you to oversell but there’s some things that should be taken into consideration first before using it:

1.make sure you have support with parallels, without it (despite their support being slow at the best of times) you will find yourself stuck now and then more so than should be expected with any production product.
2. Linux containers are great for small applications for users nothing more. A real VPS technology is the best bet for anything that’s demanding and requires real stability
3. Windows containers – In my opinion they are best only offered to perform specific tasks, i.e. a container that offers a small exchange or share point service. A multi-roled windows container is poor performing and unstable in my own experience.
4. If you want to compete in the real VPS field don’t use Virtuozzo. If you want to sell a cheap cloud solution, then it’s maybe worth a look in:)